Consultant’s report 

Dose reconstruction project 

Dr Mark Crowther, MD, MSc, FRCPC 

General comments:

In general, anything currently classified as a Leukemia (including those discussed 

below that I feel should be reclassified as leukemia) should be classified as red 

bone marrow under IMBA applicable organ, rather than “medical review”. Thus, 

in my opinion, all of the "leukemias" should be classified similarly to the 

classification currently used for acute myeloid leukemia (ICD9 205) and others. 

One could have a complicated semantic argument about whether all leukemias 

originate in the marrow; clearly, some do not but we presume that the majority 

do. Presumably the exposure causing the leukemia occurred in the marrow 

although again one could probably find examples where this is not true. 

Similarly, non-marrow exposures are probably responsible for the "lymphomas" 

and other non-leukemic hematologic malignancies. However, again, one would 

have a hard time finding good quality scientific evidence to back this up and 

there is no doubt that there are examples of non-leukemic hematologic 

malignancies where the exposure occurred in the marrow (early in leukocyte 

development) or in other non-marrow and non-lymphatic sites. 

For the purposes of this proposal I would include organs such as the thymus 

within the "lymphatic system" since it would be difficult to pin down any 

particular diseases which occurred within or outside the thymus. The lymphatic 

system can be assumed to spread widely throughout the body and although 

concentrated in the chest and abdomen it has components throughout the body. 

It is my understanding that the lymphatic system is classified with in the 

"remainder" category. 

All forms of hematological malignancy (with the possible exception of limited 

stage Hodgkin’s disease) are assumed to be widely disseminated at presentation; 

thus they are treated with systemic therapy. Hodgkin’s disease is assumed to 

start at a single location and spread to contiguous lymph node groups. Thus, 

classifying a specific site of exposure for non-Hodgkin’s hematological 

malignancies is illogical; even if the bulk of disease is confined to a single 

location (for example massive lymphadenopathy in the left cervical region) it 

cannot be assumed that this was the site of original exposure. Similarly, if a 

patient had a limited exposure (for example, radiation exposure confined to a 

limb) and later presented with a lymphoma at a remote site, it cannot be 

assumed that they are unrelated, since the exposed organ (in this case the 

lymphoreticular system) is not confined to a discrete body section or organ. 
I presume that the classification "leukemia, less CLL" is a carryover from the 

concept that CLL is not a radiation related disease. As noted, many disorders 

(for example Sezary syndrome and hairy cell leukemia as well as some forms of 

indolent lymphomas such as small lymphocytic lymphoma) behave very similarly 

to CLL and would best be classified as a CLL like disorder. However, it appears 

to me this would require the generation of a new IREP model since it is not 

included in this document. 

I realize that you are confined to ICD codes however many of the diseases 

presented are illogical; for example, I'm not sure what "subacute leukemia" is 

and many of the disorders (such as leukemias limited to body cavities) are also 

illogical. 

Specific review comments:

202.2 SEZARY DISEASE AND ALL SUBTYPES (202.20 TO 202.28) 

This would generally be regarded as a form of leukemia and thus probably is 

better classified as a “red bone marrow” disorder, rather than “Remainder”. 

Under IREP model I would suggest that they should be classified as a leukemia, 

although it would difficult to classify them as “leukemia, less CLL” since they all 

behave like CLL. 

202.4 LEUKEMIA RETICULENDOTHELIAL AND HAIRY CELL LEUKEMIA (202.4 TO 

202.48) 

These would generally be regarded as a form of leukemia and thus probably is 

better classified as a “red bone marrow” disorder, rather than “Remainder”. 

Under IREP model I would suggest that they should be classified as a leukemia, 

although it would difficult to classify them as “leukemia, less CLL” since they all 

behave like CLL. 

204.1 TO 204.11 CHRONIC LYMPHOID LEUKEMIA

These are regarded as a form of leukemia and thus should be classified as a “red 

bone marrow” disorder, rather than “NA”. Under IREP model I would suggest 

that they should be classified as a leukemia, (cannot, logically, be classified as 

“leukemia, less CLL” ; see comments above ). 

205.0 TO 205.11 ACUTE MYELOID LEUKEMIA

Not clear to me why they are classified as “Leukemia, less CLL AND Acute 

Myeloid Leukemia” – this classification is illogical since they are acute myeloid 

leukemia.